<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
	
	     	<div id="div1" style="width:200px;background:red;height:200px"></div>
	     <script >
	     	var div1=document.getElementById('div1');
	     	function getSum(){
	     		console.log(arguments.length);
	     		console.log(arguments);
	     		var sum=0;
	     		for(var i in arguments){
	     			sum+=arguments[i];
	     		}
	     		return sum;
	     	}
	     	
	     	window.onload=function(){
	     		
	     		alert(css(div1,'width'));
	     		css(div1,'background','green');
	    }
	         /* function css(){
	     		if(arguments.length==2){
	     			return arguments[0].style[arguments[1]]
	     		}else if(arguments.length==3){
	     			//div1.style.background=green;
	     			arguments[0].style[arguments[1]]=arguments[2];
	     		}else{
	     			alert("no")
	     		} 	
	     	}  */
	     	function css(obj,name,value){
	     		if(arguments.length==2){
	     			return obj.style[name];
	     		}else{
	     			obj.style[name]=value;
	     		}
	     	}
	     	
	     </script>
	</body>
</html>
